package com.ahui.ydd.controller;


import com.ahui.ydd.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    @Value("${ydd.path}")
    private String basePath;
    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){//变量名与前端传过来的name一致
        //file是一个临时文件,需要存到指定位置,否则完成请求后临时文件会删除
        log.info(file.toString());
        //获取原始文件名
        String originalFilename=file.getOriginalFilename();
        //获取文件名后缀
        String lastName = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID随机生成文件名,防止文件名重复造成覆盖
        String fileName = UUID.randomUUID().toString()+lastName;
        //创建一个目录对象,获取目录
        File dir = new File(basePath);
        //判断当前目录是否存在
        if(!dir.exists()){
            //目录不存在,创建目录
            dir.mkdirs();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath+fileName));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        //输入流,通过输入流读取文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));
            //输出流,通过输出流将文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();
            response.setContentType("image/jpeg");
            int len = 0;
            byte[] bytes = new byte[1024];
            while((len=fileInputStream.read(bytes))!= -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


}
